Hermit Crab Finds Glass Home

If you peer into one of the Wet Lab exhibits, you’ll see a widehand hermit crab (Elassochirus tenuimanus) that’s not like the others. In fact, it looks kind of… naked.

Instead of being protected by an opaque snail shell as per usual, it’s “wearing” a translucent glass shell, displaying its lower third for all to see.

Unlike other crabs, hermit crabs don’t grow a hard, protective exoskeleton over their entire bodies, so they need to protect the part of their body that is exposed with snail shells that they find on the seafloor.

Dana Turner, coordinator of curriculum programs, says, “Just like other crabs, a hermit crab moults its exoskeleton periodically to grow. Other crabs simply regrow a new, bigger exoskeleton in order to accommodate this growth but at these times, hermit crabs must also find a new, bigger (snail) shell-home too!”

Dana says people are often intrigued by how a hermit crab can squeeze its body inside such a small space and how it’s able to carry its shell-home as it wanders about. To show how this works, she called on the expertise of GlassShell, which provided a glass shell designed to mimic an Oregon triton (Fusitriton oregonensis) shell, a perceived “favourite” of the widehand hermit crab (based on observations made at the Aquarium and in the ocean).

Dana says with this, “It is now clearly visible how the soft, otherwise unprotected abdomen of the hermit crab is asymmetrical and curved to fit the spiral shape of snail shell it lives in… This is going to provide us with new teaching opportunities and will be really fantastic for the public to come and view.”